Apparatus for automatically filling conduit strings



2 Sheets-Sheet 2 INVENTOR.

Nov. 30, 1965 R. o. PARK APPARATUS FOR AUTOMATICALLY FILLING CONDUIT STRINGS Filed Jan. 12, 1962 BOBEET 0, PQQK flrromvsYs.

United States Patent 3 220,481 APPARATUS FOR A UTOMATICALLY FILLING CONDUIT STRINGS Robert 0. Park, Lakewood, Calif., assignor to Baker Oil Tools, Inc., Los Angeles, Calif., a corporation of California Filed Jan. 12, 1962, Ser. No. 165,854 20 Claims. (Cl. 166-193) The present invention relates to sursurface well apparatus, and more particularly to subsurface apparatus for controlling the filling of a conduit string, such as a string of well casing or drill pipe, with the fluid in a well bore as it is lowered therewithin.

An object of the present invention is to provide a valve apparatus adapted to be incorporated in a conduit string for controlling upward flow of fluid therein as it is lowered in a well bore, which permits downward circulation of fluid in the conduit string at any time, and which is still eflective to control subsequent upward flow of fluid in the conduit string, the apparatus being free from tendencies to plug with foreign substances in the well bore.

Another object of the invention is to provide a valve apparatus adapted to be incorporated in a conduit string for controlling upward flow of fluid therein as it is lowered in the well bore, the apparatus having an unobstructed central passage through which fluid can be pumped in a downward direction, thereby facilitating circulation of fluid through the apparatus and the pumping of cement slurry and the like therethrough.

A further object of the invention is to provide a valve apparatus adapted to be incorporated in a conduit string for controlling upward flow of fluid in the apparatus, and embodying a back pressure valve device retained initially in an ineffective position to permit upward flow in the conduit string, the apparatus being capable of being run in a tandem arrangement with the same type or other apparatus embodying a back pressure valve device initially retained in an ineffective position, the back pressure valve device being released whenever desired to provide a plu rality of such devices in series preventng back flow of fluid in the conduit string.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a longitudinal section through a well apparatus embodying the invention, with the parts in position allowing upward flow of fluid through the apparatus;

FIG. 2 is a view similar to FIG. 1 illustrating the apparatus with the parts in the position they occupy during downward circulation of fluid therethrough;

FIG. 3 is a view similar to FIG. 1 illustrating the back pressure valve device of the apparatus released to permit its upward closing;

FIG. 4 is a view similar to FIG. 3 illustrating the back 3,220,481 Patented Nov. 30, 1965 pressure valve releasing device being ejected from the apparatus;

FIG. 5 is an enlarged longitudinal section through a portion of the apparatus illustrated in FIG. 3;

FIG. 6 is a view similar to FIG. 5 illustrating the parts in another relative position.

The form of the invention illustrated in the drawings is specifically indicated as a casing collar A adapted to be incorporated in and form part of a conduit string B, such as a string of well casing, run in a well bore that contains drilling mud or similar fluid medium. The casing collar A interconnects upper and lower casing sections 10, 11 forming part of the conduit string. In lieu of being a casing collar, the apparatus A could form the lower terminal portion of the casing string, in which event it would be deemed to be a casing shoe. If desired, a plurality, such as two, of the apparatus A illustrated could be incorporated at appropriate spaced intervals in the casing string, since the apparatus is fully operable as a single unit, or as a plurality of units, embodied in the string of well casing.

As shown, the apparatus A includes an outer tubular member 12 having upper threaded box 13 for threaded attachment to the lower end of an upper casing section 10, and a lower threaded pin 14 for threaded attachment to the lower casing section 11. A valve mechanism 15 for automatically controlling upward flow of fluid in the well casing is incorporated in the outer tubular member 12, as well as a back pressure valve device 16. Such devices are contained within a cementitious plug 17 cast in the outer tubular member 12 and secured thereto, as by means of external ribs 18 on the plug received Within companion grooves 19 in the tubular member. The internal valve apparatus includes a valve housing 20, which may be formed as an upper section 21 secured to a lower section 22, as by use of pins 23. This housing 20 is attached to the cementitious plug 17 by internal ribs 24 in the cementitious plug received within external circumferential grooves 25 in the housing.

The back pressure valve device 16 is provided in the upper housing section or body 21. It includes a valve seat 26 in the upper housing section surrounding a central passage 27 communicating with an upper central passage 28 extending through the upper portion of the cementitious plug 17, the upper end 29 of this plug being tapered so as to guide fluid and other elements into the central passage 28. A back pressure valve element 30, such as a flapper valve head, is pivotally mounted on the hinge pin 31 secured to the housing section 21 and within a window or cut-out 32 at one side of the housing. This back pressure valve element 30 is urged in an upward direction into engagement with its companion valve seat 26, to prevent upward flow of fluid through the passage 27, 28, by a spring 33 of any suitable type, which may surround the hinge pin 31 and have an arm 34 bearing against the outer surface of the valve element 30.

Initially, the back pressure valve element or flapper valve head 30 is held to one side of the central passage 27 and in the window portion 32 of the housing by a tubular extension or sleeve 35' which projects upwardly into the upper housing section 21 and is disposed across the flapper valve head 30 (FIGS. 1, 2). The sleeve is piloted within the upper portion of a tubular valve member 36 forming part of a differential valve mechanis 15 for controlling the upward passage of fluid in the conduit string B as the latter is lowered in the well bore. The sleeve 35 is initially r'eleasably secured to the tubular valve member 36 by one or more shear screws 37. The valve member 36 is slid able within the lower housing section or body 22, being movable downwardly into engagement with an upwardly facing valve seat 38 formed at the upper end of the tubular hub portion 39 of a spider 40, there being circumferentially spaced ribs or legs 41 extending between the hub 39 and the lower valve housing section 22 and integral therewith, so that the hub portion 39 is fixed with respect to the lower valve housing section 22 and may be deemed to actually constitute a part thereof. The spaces 42 between the interconnecting ribs provide fairly large ports or passages through which fluid can flow, particularly in an upward direction.

Upward flow of fluid through the central hub passage 43 is prevented by a valve member 44, such as a lower flapper valve head, pivotally mounted on a hinge pin 45 mounted in a leg 46 secured to and depending from the spider 40. The lower valve head 44 is swingable upwardly into engagement with a lower valve seat 47 surrounding the hub passage 43, being urged in such upward direction by a spring 48 of any suitable type, such as one having a coil portion 49 disposed around the hinge pin 45 and an arm 49a engaging the outer surface of the lower valve head 44. The lower valve head engages the lower valve seat 47 to prevent upward flow of fluid through the central passage 43. Fluid pumped downwardly through the cementitious plug 17, the housing 20, sleeve 35 and the tubular valve member 36 will also flow through the hub passage 43, displacing the lower valve head 44 downwardly to one side, so that such fluid can pass freely down through the apparatus A.

Initially, the upper valve head 30 is held in an ineffective position to one side of the housing 22, as disclosed in FIGS. 1 and 2, by the retaining sleeve 35. Fluid can flow in an upward direction through the spider ports or passages 42, the tubular valve member 36 shifting up wardly to' allow the fluid to flow through the aligned central passages through the tubular valve member 36, sleeve 35, upper housing 21 and cementitious plug 17 for continued upward flowing through the casing or conduit sections thereabove (FIG. 1). The valve mechanism is so devised that when the fluid flowing upwardly into the conduit string B reaches a predetermined level, the tubular valve member 36 will shift downwardly int-o engagement with the upper seat 38 to prevent further upward flow of fluid into the conduit string, such as the string of well casing. Such controlled flow to a predetermined extent is provided by constituting the tubular valve member 36 in the lower housing 22 as a differential valve.

As shown, the tubular valve member 36 includes a lower portion 50 having a smaller external diameter than its upper portion 51 in which the retainer sleeve is piloted. The periphery of the lower portion slidably seals along a sealing device, including suitable sealrings 52 held against a lower housing shoulder 53 by an upper split retainer ring 54 mounted in a housing groove. The periphery of the larger diameter upper portion 51 of the tubular valve member slidably seals against a suitable seal ring device 55' hearing against an upwardly facing shoulder 56 in the housing section 22 and held thereagainst by an upper retainer ring 57 received within a groove 58 in the housing section or body. The annular space 59 between the housing 22 and the tubular valve member 36 and between the upper and lower seals 55, 52 initially contains air at atmospheric pressure, the upper and lower seals preventing the well bore fluid from entering this space. As a result, the fluid in the well bore externally of the casing string B, which can pass around to its interior below the valve mechanism 15, flows through the lower spider ports 42 and can act in an upward direction on the tubular valve member over the annular area R, tending to shift the valve 36 in an upward direction, or to an open position, to the extent limited by engagement of the upper end 69a of the valve member with the lower 'end of the upper housing section 21. The fluid in the tubular string B above the valve mechanism 15 acts downwardly on the tubular valve member 36 over the annular area S of its upper larger portion 51, which area is greater than the lower annular area R. As a result,'when the hydrostatic; head of fluid within the conduit string B above the ap paratus A reaches a predetermined level, which is less than the head of fluid in the well bore externally of the apparatus, the valve member 36 will be shifted downwardly to bring its lower end into engagement with the valve seat 38; whereupon further upward flow of fluid in the" conduit string B cannot occur, until the latter is lowered to a further extent in the fluid in the well bore. During the entire travel of the tubular valve member 36 between its fully open position upwardly from engagement with its companion valve seat 38 (FIG. 1), and its fully closed position in engagement therewith (FIG. 2), the tubular extension or retainer sleeve 35 secured thereto by the shear screws 37 will be disposed partially across the upper back pressure valve element 30 to retain it to one side of the passage 27 and prevent its upward movement into engagement with its companion valve seat 26.

At any time during the lowering of the string of well casing B, or other conduit string, through the fluid in the well bore, downward circulation through the conduit string can take place, without preventing subsequent functioning of the valve mechanism 15 in controlling the upward passage of fluid in the well casing. When circulation is desired, the conduit string is filled to the top of the hole; whereupon fluid can be pumped downwardly in the casing. Such fluid will pass through the upper central passages 28, 27 in the cem'entitious plug 17 and upper housing 21, through the retainer sleeve 35 and. tubular valve member 36 into the hub passage 43, unseating the lower valve head 44 from its seat 47 and displacing it to one side, such as disclosed in FIG. 2, the fluid flowing downwardly completely out of the apparatus A and out of the well casing, usually passing upwardly around the casing and back toward the top of the well bore. When circulation ceases, the lower flapper valve head 44 will move back into engagement with its lower seat 47.

Lowering of the conduit string B in the well bore can continue. The tubuar valve member 36 will remain engaged with its seat 38 until the hydrostatic head of fluid in the conduit string lowers relative to the external head of fluid to a desired extent; whereupon the tubular valve member 36 will be shifted by the external head of fluid upwardly to an open position (FIG. 1), allowing the fluid to flow through the ports 42 and upwardly through the tubular valve device 36, retainer sleeve 35, upper housing 21 and plug passage 28 into the conduit string thereabove. When the fluid level within the conduit string reaches the predetermined level with respect to the external fluid level, the tubular valve member 36 will shift automatically back down into engagement with its seat 38, preventing further upward flow of fluid in the conduit string B.

If desired, circulation can again be established without affecting the ability of the filling valve 15 to subsequently function in controlling the filling of the conduit string with the fluid in the well bore. Such circulation can occur as ofter as desired during lowering of the conduit string B in the well bore, and, for that matter, after it has been lowered to its final position in the well bore.

If, for any reason, the back pressure valve element 30 is to be released, a tripping valve element 60, such as a ball, can be dropped into the conduit string B or pumped downwardly therethrough, this ball moving down within the: retainer sleeve 35 and coming to rest upon a lower valve seat 61 projecting inwardly of the wall of the sleeve to a small extent. Pressure can then be built up in the conduit string B above the retainer sleeve 35 and ball member to a suificient value to overcome the shear strength of the screws 37, the tubular valve member 36 being in engagement with its companion seat 38, the shear screws being disrupted and the sleeve 35 shifting downwardly in the tubular valve member 36 and out of engagement with the back pressure valve element 30, which is then released and capable of moving upwardly into engagement with its companion valve seat 26 to prevent subsequent upward flow of fluid through the apparatus. However, the tripping valve element 60 is now in a position to prevent downward flow of fluid in the apparatus A. Such valve element 60 may be completely ejected from the apparatus A, so that downward circulation of fluid through the latter can occur.

As disclosed, the sleeve 35 has an enlarged upper portion 62 providing a downwardly facing stop shoulder 63 adapted to engage the upper end 60a of the tubular valve member 36 and thereby limiting the extent of downward movement of the sleeve 35 within the tubular valve member. At this time, the lower portion 64 of the sleeve 35, which includes its valve seat 61, is disposed opposite an internal relief groove 65 in the tubular valve member 36, the inner wall of this groove having a substantially greater diameter than the diameter of the lower portion 64 of the sleeve 35. The lower portion 64, in the region of the valve seat 61 and extending a slight distance thereabove, has a center or weakened section 66 provided by an external groove 67 therearound, which will permit outward deflection of the lower valve seat portion 64 into the relief groove 65 when sufficient lateral force is exerted thereon. Such outward deflection can occur to an extent to increase the diameter of the valve seat 61 to a value slightly greater than the diameter of the ball valve element 60, so that the latter can pass downwardly through the valve seat 61.

As disclosed in FIGS. 3 to 6, inclusive, the ball valve element 60 has a diameter slightly greater than the initial minimum diameter through the sleeve valve seat 61. With the shear screws 37 intact, the weakened portion 66 of the sleeve 35 is backed up by the surrounding inner wall of the tubular valve member 36 (FIGS. 1, 2). Accordingly, when the ball valve element 60 engages the seat 61, suflicient pressure can be imposed on the ball and sleeve 35 to shear the screws 37, the valve seat 61 being prevented from expanding outwardly by the confining wall of the tubular valve member. Accordingly, the ball 60 and the sleeve 3 shift downwardly to the position illustrated in FIGS. 3 and 5. At that, the force required to stretch the valve seat 61 laterally outwardly can be substantially greater than the force required to shear the screws 37, even in the absence of the confining wall of the tubular valve member 36. In any event, when the back pressure valve element 30 has been released and the sleeve 35 shifted downwardly, as shown in FIGS. 3 and 5, sufficient pressure, which may substantially exceed the pressure required to shear the screws 37, can be imposed on the ball 60, the ball urging and stretching the valve seat 61 in an outward direction, such as shown most clearly in FIGS. 4 and 6, until the ball 60 is forced through the valve seat 61, continuing on down through the tubular valve member 36 and the passage 43 through the hub, unseating the lower valve head 44 and being forced downwardly completely out of the apparatus A.

Downward circulation of fluid in the well casing B can then occur. However, upward flow of fluid cannot occur since the back pressure valve member 30 can swing upwardly into engagement with its companion seat 26. After the well has been properly conditioned, cement slurry, or the like, can be pumped down through the casing string B, displacing the back pressure valve 30 to one side and continuing its passage down through the sleeve 35, tubular valve member 36 and hub passage 43, displacing the lower valve head 44 to one side for continued downward movement through the conduit string and for outward passage from the latter. The relieving of the pressure in the conduit string B will then permit the lower valve member 44 to move back into engagement with its seat 47, which, by itself, in ineffective to prevent upward flow of fluid through the apparatus.

6 However, the upper valve member 30 will also swing upwardly into engagement with its companion seat 26, preventing return flow of cement slurry or other fluid upwardly through the apparatus.

Because of the apparatus illustrated and described, downward circulation of fluid can occur whenever desired, while upward filling of the conduit string B is under the control of the lower valve mechanism 15. Downward circulation occurs through a straight-through central passage, which results in less exposure of the parts to erosion despite extensive circulation of fluid through the apparatus. The apparatus A is not susceptible to plugging as a result of solid materials encountered in the well bore, and even if plugging were to occur, the large diameter straight-through central pasageway for the circulating fluid insures the ready removal of the plugging material. Downward circulation through the apparatus can be established at any time, followed by controllable filling of the conduit string thereafter. At any time, the valve element 60 can be lowered into engagement with its companion valve seat 61 for the purpose of releasing the back pressure valve element 30; whereupon subsequent filling of the conduit string through the apparatus cannot occur.

The apparatus is of such character that two or more piece of equipment can be incorporated at predetermined locations in the conduit string. For example, two devices A can be incorporated in the conduit string, both of them providing a controlled automatic fluid fill of the latter, and both of them embodying back pressure valve devices 30 which are initially held in an ineffective position, but which can be released whenever desired. When the back pressure valves are to be released, the ball valve element 60 is lowered through the conduit string B and will engage the upper sleeve seat 61 of the upper apparatus. The increase in pressure above the ball valve member 60 will result in shearing of the screws 37 and the lowering of the sleeve 35 from engagement with its back pressure valve element 30, the sleeve shifting to a downward postion in which its seat 61 is opposite the relief groove 65. An increase of pressure on the ball valve element 60 will then cause the latter to swedge the seat 61 outwardly, the ball 60 being ejected therethrough and passing down through the tubular member 36 and the central hug passage 43, displacing the lower valve head 44 from its path and continuing on downwardly into engagement with the sleeve seat 61 of a lower device A. An increase in the pressure above the valve element 61 and the lower device will then result in the shearing of the screws 37 holding the lower sleeve 36 to its tubular valve member 36, the sleeve shifting downwardly within the latter from engagement with its companion back pressure valve member 30, then allowing the latter to swing upwardly into engagement with its seat 26. Again an increase in the pressure acting on the ball valve element 60 will cause it to swedge the seat 61 outwardly, resulting in downward ejection of the ball valve element 60 from the lower apparatus A, the valve element being pumped outwardly into the well bore.

Circulating fluid can now be pumped downwardly through the conduit string B, passing downwardly through both the tandem arrangement of upper and lower valve apparatus for discharge into the well casing. A suitable charge of cement slurry can also be pumped down the casing string, passing downwardly through both the upper apparatus A and the lower apparatus A for discharge into the well bore. The back pressure valves 30 of both the upper apparatus and the lower apparatus are then effective to insure against return flow of cement slurry into the conduit string.

I claim:

1. In well apparatus: a tubular member having means thereon for securing said member in a conduit string to be lowered in a well bore; body means providing a central fluid passage in said member through which fluid passing downwardly in said tubular member can flow; a valve element movable upwardly into engagement with said body means to seal against said body means and provide a barriar across the axis of said body means closing said central passage against upward flow of fluid; said body means having a by-pass passage around said element through which fluid can flow when said element closes said central passage; and valve means in said tubular member movable upwardly therein to a position allowing upward flow of fluid through said by-pass passage and through said tubular member and movable downwardly in said tubular member to another position preventing upward flow through said by-pass passage.

2. In well apparatus: a tubular member having means thereon for securing said member in a conduit string to be lowered in a well bore; body means in said tubular member providing a central fluid passage in said member, said body means having an upper valve seat and a lower valve seat, both surrounding said passage; first valve means movable upwardly into engagement with said lower valve seat to prevent upward flow of fluid past said lower seat and through said central passage; said body means having a by-pass passage around said valve element through which fluid can flow when said element engages said lower seat; second valve means in said tubular member movable downwardly into engagement with said upper seat to prevent upward flow of fluid past said upper seat and said by-pass passage and through said tubular member, said second valve means being movable upwardly from engagement with said upper seat to open said by-pass passage.

3. In well apparatus: a tubular member having means thereon for securing said member in a conduit string to be lowered in a well bore; body means in said tubular member providing a central fluid passage in said member, said body means having an upper valve seat and a lower valve seat, both surrounding said passage; first valve means movable upwardly into engagement with said lower valve seat to prevent upward flow of fluid past said lower seat and through said central passage; said body means having a by-pass passage around said valve element through which fluid can flow when said element engages said lower seat; tubular valve means in said tubular member movable downwardly into engagement with said upper seat to prevent upward flow of fluid past said upper seat and through said by-pass passage and through said tubular member, said tubular valve means being movable upwardly from engagement with said upper seat to open said by-pass passage, said tubular valve means enabling fluid to be pumped downwardly into said tubular member for downward passage through said tubular valve means and central passage and shifting said first valve means from said lower seat.

4. In well apparatus: a tubular member having means thereon for securing said member in a conduit string to be lowered in a well bore; body means in said tubular member providing a central fluid passage in said member, said body means having an upper valve seat and a lower valve seat, both surrounding said passage; a valve element pivotally mounted on said body means and swingable upwardly into engagement with said lower valve seat to prevent upward flow of fluid past said lower seat and through said central passage; said body means having a by-pass passage around said valve element through which fluid can flow when said element engages said lower seat; a valve member in said tubular member movable downwardly into engagement with said upper seat to prevent upward flow of fluid past said'upper seat and through said by-pass passage and through said tubular member, said valve member being movable upwardly from engagement with said upper seat to open said by-pass passage.

5. In well apparatus: a tubular member having means thereon for securing said member in a conduit string to be lowered in a well bore; back pressure valve means in said member permitting downward flow of fluid in said tubular member and shiftable to a closed position preventing upward flow of fluid in said tubular member; means in said tubular member for preventing said back pressure valve means from being shifted to closed position; and means engageable with said preventing means for shifting said preventing means to a position permitting closing of said back pressure valve means; means enabling said shifting means to be moved from said preventing means, following release of said preventing means from said back pressure valve means, and movable downwardly from said tubular member; and means retaining said preventing means in said tubular member during and after movement of said shifting means from said preventing means.

6. In well apparatus; a tubular member having means thereon for securing said member in a conduit string to be lowered in a well bore; back pressure valve means in said member permitting downward flow of fluid in said tubular member and shiftable to a closed position preventing upward flow of fluid in said tubular member; means for preventing said back pressure valve means from being shifted to closed position; said preventing means having a valve seat device; a trip device engageable with said valve seat device and responsive to fluid pressure in said tubular member to shift said preventing means downwardly in said tubular member to a position permitting closing of said back pressure valve means; at least one of said devices having a laterally shiftable portion to enable said trip device to pass downwardly through said valve seat device and from said tubular member following release of said preventing means from said back pressure valve means.

7. In well apparatus: a tubular member having means thereon for securing said member in a conduit string to be lowered in a well bore; back pressure valve means in said member permitting downward flow of fluid in said tubular member and shiftable to a closed position pre- .venting upward flow of fluid in said tubular member; means for preventing said back pressure valve means from being shifted to closed position; said preventing means having an outwardly swedgable valve seat; trip means engageable with said valve seat and responsive to fluid pressure in said tubular member to shift said preventing means downwardly in said tubular member to a position permitting closing of said back pressure valve means; said trip mean being responsive to fluid pressure in said tubular member to swedge said valve seat outwardly and enable said trip means to pass downwardly through said valve seat following release of said preventing means from said back pressure valve means.

8. In well apparatus: a tubular member having means thereon for securing said member in a conduit string to be lowered in a well bore; back pressure valve means in said member permitting downward flow of fluid in said tubular member and shiftable to a closed position preventing upward flow of fluid in said tubular member; means for preventing said back pressure valve means from being shifted to closed position; said preventing means having a valve seat; trip means engageable with said valve seat and responsive to fluid pressure in said tubular member to shift said preventing means downwardly in said tubular member to a position permitting closing of said back pressure valve means; stop means in said tubular member limiting downward movement of said preventing means therein following release of said preventing means from said back pressure valve means; said trip means and valve seat being so constructed and arranged that said trip means passes downwardly through said valve seat and from said tubular member following engagement of said preventing means with said stop means.

9. In well apparatus: a tubular member having means thereon for securing said member in a conduit string to be lowered in a well bore; back pressure valve means in said member permitting downward flow of fluid in said tubular member and shiftable to a closed position preventing upward flow of fluid in said tubular member; means for preventing said back pressure valve means from being shifted to closed position; said preventing means having an outwardly swedgable valve seat; trip means engageable with said valve seat and responsive to fluid pressure in said tubular member to shift said preventing means downwardly in said tubular member to a position permitting closing of said back pressure valve means; stop means in said tubular member limiting downward movement of said preventing means therein following release of said preventing means from said back pressure valve means; said trip means being responsive to fluid pressure in said tubular member to swedge said valve seat outwardly and enable said trip means to pass downwardly through said valve seat following engagement of said preventing means with said stop means.

10. In well apparatus: a tubular member having means thereon for securing said member in a conduit string to be lowered in a well bore; back pressure valve means in said member permitting downward flow of fluid in said tubular member and shiftable to a closed position preventing upward flow of fluid in said tubular member; means comprising a sleeve having a valve seat device and engageable with said back pressure valve means for preventing said back pressure valve means from being shifted to closed position; a trip device movable downwardly into engagement with said valve seat device and responsive to fluid pressure in said tubular member to shift said sleeve downwardly in said tubular member to a position permitting closing of said back pressure valve means; at least one of said devices having a laterally shiftable portion to enable said trip device to pass downwardly through said valve seat device and from said tubular member following release of said sleeve from said back pressure valve means.

11. In well apparatus: a tubular member having means thereon for securing said member in a conduit string to be lowered in a well bore; back pressure valve means in said member permitting downward flow of fluid in said tubular member and shiftable to a closed position preventing upward flow of fluid in said tubular member; means comprising a sleeve having a valve seat and engageable with said back pressure valve means for preventing said back pressure valve means from being shifted to closed position; trip means movable downwardly into engagement with said valve seat and responsive to fluid pressure in said tubular member to shift said sleeve downwardly in said tubular member to a position permitting closing of said back pressure valve means; stop means in said tubular member limiting downward movement of said sleeve therein following release of said sleeve from said back pressure valve means; said trip means and valve seat being so constructed and arranged that said trip means passes downwardly through said valve seat and from said tubular member following eugagement of said sleeve with said stop means.

12. In well apparatus: a tubular member having means thereon for securing said member in a conduit string to be lowered in a well bore; body means providing a central fluid passage in said member through which fluid passing downwardly in said tubular member can flow; a valve element movable upwardly into engagement with said body means to seal against said body means and close said central passage against upward flow of fluid; said body means having a by-pass passage around said element through which fluid can flow when said element closes said central passage; valve means in said tubular member movable upwardly therein to a position allowing upward flow of fluid through said by-pass passage and through said tubular member and movable downwardly in said tubular member to another position preventing upward flow through said by-passage; back pressure valve means in said tubular member permitting downward flow of fluid in said tubular member and shiftable to a closed position preventing upward flow of fluid in said tubular' member; means for preventing said back pressure valve means from being shifted to closed position; and means engageable with said preventing means for shifting said preventing means to a position permitting closing of said back pressure valve means, said shifting means being adapted to be moved from said preventing means, following release of said preventing means from said back pressure valve means, and movable downwardly from said tubular member.

13. In well apparatus: a tubular member having means thereon for securing said member in a conduit string to be lowered in a well bore; body means in said tubular member providing a central fluid passage in said member, said body means having an upper valve seat and a lower valve seat, both surrounding said passage; a valve element movable upwardly into engagement with said lower valve seat to prevent upward flow of fluid past said lower seat and through said central passage; said body means having a by-pass passage around said valve element through which fluid can flow when said element engages said lower seat; a tubular valve member in said tubular member movable downwardly into engagement with said upper seat to prevent upward flow of fluid past said upper seat and through said by-pass passage and through said tubular member, said tubular valve member being movable upwardly from engagement with said upper seat to open said by-pass passage, said tubular valve member enabling fluid to be pumped downwardly into said tubular member for downward passage through said tubular valve member and central passage and shifting said valve element from said lower seat; back pressure valve means in said tubular member permitting downward flow of fluid in said tubular member and shiftable to a closed position preventing upward flow of fluid in said tubular member; means for preventing said back pressure valve means from being shifted to closed position; and means engageable with said preventing means for shifting said preventing means to a position permitting closing of said back pressure valve means, said shifting means being adapted to be moved from said preventing means, following release of said preventing means from said back pressure valve means, and movable downwardly through said tubular valve member and central passage and from said tubular member.

14. In well apparatus: a tubular member having means thereon for securing said member in a conduit string to be lowered in a well bore; body means in said tubular member providing a central fluid passage in said member, said body means having an upper valve seat and a lower valve seat, both surrounding said passage; a valve element pivotally mounted on said body means and swingable upwardly into engagement with said lower valve seat to prevent upward flow of fluid past said lower seat and through said central passage; said body means having a by-pass passage around said valve element through which fluid can flow when said element engages said lower seat; a valve member in said tubular member movable downwardly into engagement with said upper seat to prevent upward flow of fluid past said upper seat and through said by-pass passage and through said tubular member, said valve member being movable upwardly from engagement with said upper seat to open said by-pass passage; back pressure valve means in said tubular member permitting downward flow of fluid in said tubular member and shiftable to a closed position preventing upward flow of fluid in said tubular member; means for preventing said back pressure valve means from being shifted to closed position; and means engageable with said preventing means for shifting said preventing means to a position permitting closing of said back pressure valve means, said shifting means being adapted to be moved from said preventing means, following release of said preventing means from said back pressure valve means, and movable downwardly through said tubular valve member and central passage and from said tubular member.

15. In well apparatus: a tubular member having means thereon for securing said member in a conduit string to be lowered in a well bore; body means in said tubular member providing a central fluid passage in said member, said body means having an upper valve seat and a lower valve seat, both surrounding said passage; a valve element movable upwardly into engagement with said lower valve seat to prevent upward flow of fluid through said central passage; said body means having a by-pass passage around said valve element through which fluid can flow when said element engages said lower seat; a tubular valve member in said tubular member movable downwardly into engagement with said upper seat to prevent upward flow of fluid through said by-pass passage and through said tubular member, said tubular valve member being movable upwardly from engagement with said upper seat to open said by-pass passage, said tubular valve member enabling fluid to be pumped downwardly into said tubular member for downward passage through said tubular valve member and central passage and shifting said valve element from said lower seat; back pressure valve means in said tubular member permitting downward flow of fluid in said tubular member and shiftable to a closed position preventing upward flow of fluid in said tubular member; means for preventing said back pressure valve means from being shifted to closed position; said preventing means having a trip valve seat; trip means engageable with said trip valve seat and responsive to fluid pressure in said tubular member to shift said preventing means downwardly in said tubular member to a position permitting closing of said back pressure valve means; said trip means and trip valve seat being so constructed and arranged that said trip means passes downwardly through said trip valve seat, through said tubular valve member, central passage, and from said tubular member following release of said preventing means from said back pressure valve means.

16. In well apparatus: a tubular member having means thereon for securing said member in a conduit string to be lowered in a well bore; body means in said tubular member providing a central fluid passage in said member, said body means having an upper valve seat and a lower valve seat, both surrounding said passage; a valve element movable upwardly into engagement with said lower valve seat to prevent upward flow of fluid through said central passage; said body means having a by-pass passage around said valve element through which fluid can flow when said elements engages said lower seat; a tubular valve member in said tubular member movable downwardly into engagement with said upper seat to prevent upward flow of fluid through said by-pass passage and through said tubular member, said tubular valve member being movable upwardly from engagement with said upper seat to open said by-pass passage, said tubular valve member enabling fluid to be pumped downwardly into said tubular member for downward passage through said tubular valve member and central passage and shifting said valve element from said lower seat; back pressure valve means in said tubular member permitting downward flow of fluid in said tubular member and shiftable to a closed position preventing upward flow of fluid in said tubular member; means for preventing said back pressure valve means from being shifted to closed position; said preventing means having an outwardly swedgable trip valve seat; trip means engageable with said trip valve seat and responsive to fluid pressure in said tubular member to shift said preventing means downwardly in said tubular member to a position permitting closing of said back pressure valve means; said trip means being responsive to fluid pressure in said tubular member to swedge said trip valve seat outwardly and enable said trip means to pass downwardly through said trip valve seat, tubular valve member, central passage and from said tubular member following release of said preventing means from said back pressure valve means.

17. In well apparatus: a tubular member having means thereon for securing said member in a conduit string to be lowered in a well bore; body means in said tubular member providing a central fluid passage in said member, said body means having an upper valve seat and a lower valve seat, both surrounding said passage; a valve element movable upwardly into engagement with said lower valve seat to prevent upward flow of fluid through said central passage; said body means having a bypass passage around said valve element through which fluid can flow when said element engages said lower seat; a tubular valve member in said tubular member movable downwardly into engagement with said upper seat to prevent upward flow of fluid through said by-pass passage and through said tubular member, said tubular valve member being movable upwardly from engagement with said upper seat to open said by-pass passage, said tubular valve member enabling fluid to be pumped downwardly into said tubular member for downward passage through said tubular valve member and central passage and shifting said valve element from said lower seat; back pressure valve means in said tubular member permitting downward flow of fluid in said tubular member and shiftable to a closed position preventing upward flow of fluid in said tubular member; means comprising a sleeve having an outwardly swedgable trip valve seat and engageable with said back pressure valve means for preventing said back pressure valve means from being shifted to a closed position; trip means movable downwardly into engagement with said trip valve seat and responsive to fluid pressure in said tubular member to shift said sleeve downwardly in said tubular member to a position permitting closing of said back pressure valve means; stop means in said tubular member limiting downward movement of said sleeve therein following release of said sleeve from said back pressure valve means; said trip means being responsive to fluid pressure in said tubular member to swedge said trip valve seat outwardly and enable said trip means to pass downwardly through said trip valve seat, tubular valve member, central passage and from said tubular member following engagement of said sleeve with said stop means.

18. In well apparatus: a tubular member having means thereon for securing said member in a conduit string to be lowered in a well bore; body means in said tubular member providing a central fluid passage in said member, said body means having an upper valve seat and a lower valve seat, both surrounding said passage; a valve element movable upwardly into engagement with said lower valve seat to prevent upward flow of fluid through said central passage; said body means having a by-pass passage around said valve element through which fluid can flow when said element engages said lower seat; a tubular valve member in said tubular member movable downwardly into engagement with said upper seat to prevent upward flow of fluid through said by-pass passage and through said tubular member, said tubular valve member being movable upwardly from engagement with said upper seat to open said by-pass passage, said tubular valve member enabling fluid to be pumped downwardly into said tubular member for downward passage through said tubular valve member and central passage and shifting said valve element from said lower seat; back pressure valve means in said tubular member permitting downward flow of fluid in said tubular member and shiftable to a closed position preventing upward flow of fluid in said tubular member; means comprising a sleeve piloted in and releasably connected to said tublar valve member, said sleeve having an outwardly swedgable trip valve seat and being engageable with said back pressure valve means for preventing said back pressure valve means from being shifted to closed position; trip means movable downwardly into engagement with said trip valve seat and responsive to fluid pressure in said tubular member to release said sleeve from said tubular valve member and shift said sleeve downwardly therewithin to a position permitting closing of said back pressure valve means; said sleeve and tubular valve means having eoengaging means limiting downward movement of said sleeve in said tubular valve member; said trip means being responsive to fluid pressure in said tubular member to swedge said trip valve seat outwardly and enable said trip means to pass downwardly through said trip valve seat, tubular valve member, central passage and from said tubular member following engagement of said stop means on said sleeve and tubular valve member.

19. In Well apparatus: a tubular member having means thereon for securing said member in a conduit string to be lowered in a well bore; body means in said tubular member providing a central fluid passage in said member, said body means having an upper valve seat and a lower valve seat, both surrounding said passage; a valve element movable upwardly into engagement with said lower valve seat to prevent upward flow of fluid through said central passage; said body means having a by-pass passage around said valve element through which fluid can flow when said element engages said lower seat; a tubular valve member in said tubular member movable downwardly into engagement with said upper seat to prevent upward flow of fluid through said by-pass passage and through said tubular member, said tubular valve memher being movable upwardly from engagement with said upper seat to open said by-pass passage, said tubular valve member enabling fluid to be pumped downwardly into said tubular member for downward passage through said tubular valve member and central passage and shifting said valve element from said lower seat; back pressure valve means in said tubular member permitting downward flow of fluid in said tubular member and shiftable to a closed position preventing upward flow of fluid in said tubular member; means comprising a sleeve piloted in and releasably connected to said tubular valve member, said sleeve having an outwardly swedgable trip valve seat and being engageable with said back pressure valve means for preventing said back pressure valve means from being shifted to closed position; trip means movable downwardly into engagement with said trip valve seat and responsive to fluid pressure in said tubular member to release said sleeve from said tubular valve member and shift said sleeve downwardly therewithin to a position permitting closing of said back pressure valve means; said sleeve and tubular valve means having coengaging means limiting downward movement of said sleeve in said tubular valve member; said tubular valve member having a relief groove opposite said tn'p valve seat when said sleeve has been shifted downwardly in said tubular valve member; said trip means being responsive to fluid pressure in said tubular member to swedge said trip valve seat outwardly and the portion of said sleeve therearound outwardly into said relief groove to enable said trip means to pass downwardly through said trip valve seat, through said tubular valve member, central passage and from said tubular member following engagement of said sleeve with said tubular valve member.

20. In well apparatus: a tubular member having means thereon for securing said member in a conduit string to be lowered in a well bore; back pressure valve means in said member permitting downward flow of fluid in said tubular member and shiftable to a closed position preventing upward flow of fluid in said tubular member; means comprising a sleeve having an outwardly swedgable trip valve seat and engageable with said back pressure valve means for preventing said back pressure valve means from being shifted to a closed position; trip means movable downwardly into engagement wtih said trip valve seat and responsive to fluid pressure in said tubular member to shift said sleeve downwardly in said tubular member to a position permitting closing of said back pressure valve means; stop means in said tubular member limiting downward movement of said sleeve therein, following release of said sleeve from said back pressure valve means; means providing a relief groove opposite said trip valve seat when said stop means has limited such downward movement of said sleeve; said trip means being responsive to fluid pressure in said tubular member to swedge said trip valve seat outwardly and the portion of said sleeve therearound outwardly into said relief groove to enable said trip means to pass downwardly through said valve seat and from said tubular member following engagement of said sleeve with said stop means.

References Cited by the Examiner UNITED STATES PATENTS 2,841,171 7/1958 Baker et al. 166-224 X 3,011,559 12/1961 Muse et al. 166-225 3,013,612 12/1961 Angel 166225 3,123,517 3/1964 Davis 166 224 CHARLES E. OCONNELL, Primary Examiner, 

16. IN WELL APPARATUS: A TUBULAR MEMBER HAVING MEANS THEREON FOR SECURING SAID MEMBER IN A CONDUIT STRING TO BE LOWERED IN A WELL BORE; BODY MEANS IN SAID TUBULAR MEMBER PROVIDING A CENTRAL FLUID PASSAGE IN SAID MEMBER, SAID BODY MEANS HAVING AN UPPER VALVE SEAT AND A LOWER VALVE SEAT, BOTH SURROUNDING SAID PASSAGE; A VALVE ELEMENT MOVABLE UPWARDLY INTO ENGAGEMENT WITH SAID LOWER VALVE SEAT TO PREVENT UPWARD FLOW OF FLUID THROUGH SAID CENTRAL PASSAGE; SAID BODY MEANS HAVING A BY-PASS PASSAGE AROUND SAID VALVE ELEMENT THROUGH WHICH FLUID CAN FLOW WHEN SAID ELEMENTS ENGAGES SAID LOWER SEAT; A TUBULAR VALVE MEMBER IN SAID TUBLAR MEMBER MOVABLE DOWNWARDLY INTO ENGAGEMENT WITH SAID UPPER SEAT TO PREVENT UPWARD FLOW OF FLUID THROUGH SAID BY-PASS PASSAGE AND THROUGH SAID TUBULAR MEMBER, SAID TUBULAR VALVE MEMBER BEING MOVABLE UPWARDLY FROM ENGAGEMENT WITH SAID UPPER SEAT TO OPEN SAID BY-PASS PASSAGE, SAID TUBULAR VALVE MEMBER ENABLING FLUID TO BE PUMPED DOWNWARDLY INTO SAID TUBULAR MEMBER FOR DOWNWARD PASSAGE THROUGH SAID TUBULAR VALVE MEMBER AND CENTRAL PASSAGE AND SHIFTING SAID VALVE ELEMENT FROM SAID LOWER SEAT; BACK PRESSURE VALVE MEANS IN SAID TUBULAR MEMBER PERMITTING DOWNWARD FLOW OF FLUID IN SAID TUBULAR MEMBER AND SHAFTABLE TO A CLOSED POSITION PREVENTING UPWARD FLOW OF FLUID IN SAID TUBULAR MEMBER; MEANS FOR PREVENTING SAID BACK PRESSURE VALVE MEANS FROM BEING SHIFTED TO CLOSED POSITION; SAID PREVENTING MEANS HAVING AN OUTWARDLY SWEDGABLE TRIP VALVE SEAT; TRIP MEANS ENGAGEABLE WITH SAID TRIP VALVE SEAT AND RESPONSIVE TO FLUID PRESSURE IN SAID TUBULAR MEMBER TO SHIFT SAID PREVENTING MEANS DOWNWARDLY IN SAID TUBULAR MEMBER TO A POSITION PERMITTING CLOSING OF SAID BACK PRESSURE VALVE MEANS; SAID TRIP MEANS RESPONSIVE TO FLUID PRESSURE IN SAID TUBULAR MEMBER TO SWEDGE SAID TRIP VALVE SEAT OUTWARDLY AND ENABLE SAID TRIP MEANS TO PASS DOWNWARDLY THROUGH SAID TRIP VALVE SEAT, TUBULAR VALVE MEMBER, CENTRAL PASSAGE AND FROM SAID TUBULAR MEMBER FOLLOWING RELEASE OF SAID PREVENTING MEANS FROM SAID BACK PRESSURE VALVE MEANS. 